I just found this Interesting fan-art that has many of the official, unofficial and non Vocaloid voice synthesizers. It's not all of them as its missing many of the newer Vocaloids and a bajillion Miku variants but still interesting non the less. I had to cut it up into a bunch of pieces so i could even upload it here as it wasn't even close to meting the MAS image size restrictions. XD I wonder if anyone can recognize them all? (I only knew about a third)